Applying geoscience to Australia's most important challenges

U-K-A. Wandoan No. 1, Queensland Of Union Oil Development Corporation Kern County Land Company And Australian Oil And Gas
Corporation Limited

Abstract

Union - Kern - A.O.G. Wandoan No. 1 was the first wildcat drilled by Union Oil Development Corporation in the north-eastern
part of the Surat Basin. Union - Kern A. O.G. Moonie No. 1 had proven the potential of the Jurassic-Triassic Precipice Sandstone
as an oil reservoir and it was necessary to evaluate this reservoir in other parts of the basin. In the Wandoan area seismic
surveys defined a large north-plunging anticline in rocks of the Bowen Group, with a domal closure in the Great Artesian Group
superimposed on the north plunge of the feature. This domal closure shows more than 200 feet of vertical closure encompassing
an area of 30 square miles. The Wandoan well was programmed primarily to test the petroleum potential of the Precipice Sandstone
on this closure.
Drilling commenced on 22nd April, 1962 and the well was completed on 18th June, 1962 as a dry hole at a total depth of 10,736
feet. A full programme of logging, testing, and coring was undertaken.
Wandoan No. 1 Well established the presence of4798 feet of Mesozoic sediments of the Great Artesian Group resting disconformably
on 5919 feet of Lower Mesozoic-Upper Palaeozoic strata of the Bowen Group. Testing over the interval 3260 to 3278 feet indicated
that the Precipice Sandstone has excellent reservoir characteristics. Yellowish to bluishwhite fluorescence in the samples,
and traces of hydrocarbons in the formation water from this interval indicated that hydrocarbons have migrated through the
sandstone. Fluorescence and minor gas shows in the upper part of the Bowen Group were noted but the reservoir characteristics
of these rocks were unfavourable for an accumulation of oil and gas.
The well bottomed at 10,736 feet in coals and tuffs of the Kianga Formation. Cement plugs were set and the well was abandoned
on 21st June, 1962.